Axis Minor

The ellipsoid of revolution is swept out by rotating an ellipse along its major or minor axis. When the major axis is the axis of rotation, the resulting rodlike figure is said to be prolate when the minor axis is the axis of rotation, the disklike figure is said to be oblate. 

Oblate Spheroid (formed by the rotation of an ellipse about its minor axis [ ]) Data as given previously. 

Hemi-ellipsoidal Heads have an ellipsoidal cross section, usually with minor axis equal to one half the major axis—that is, depth = Vi D, or more. 

Aspect ratio It is the ratio of length to diameter of a material such as a rod or fiber also the ratio of the major to minor axis lengths of a material such as a product. 

Figure 4. Segment at the end of the semi-minor axis, b, of an ellipsoid (left), and use of a test plate and auxiliary convex mirror to shorten the optical path of the test (right).

For an ellipse with major axis 2a and minor axis 2b, it can be shown that (see any standard geometry text) ... 

Most standard ellipsoidal heads are manufactured with a major and minor axis ratio of 2 1. For this ratio, the following equation can be used to calculate the minimum thickness required ... 

Ellipsoid If the base of a vessel is one-half of an oblate spheroid (the cross section fitting to a cylinder is a circle with radius of D/2 and the minor axis is smaller), then use the formulas for one-half of an oblate spheroid. 

A mud slurry is drained from a tank through a 50 ft long plastic hose. The hose has an elliptical cross section with a major axis of 4 in. and a minor axis of 2 in. The open end of the hose is 10 ft below the level in the tank. The mud is a Bingham plastic, with a yield stress of 100 dyn/cm2, a limiting viscosity of 50 cP, and a density of 1.4g/cm3. 

Since the cross-section of a cylinder by the nearly flat Ewald sphere is an ellipse, equation (10) evaluates the length of the minor axis of this ellipse. 

Another way to define the direction of the minor axis is to manually locate it by choosing a single reflection lying on the axis. The disadvantages of this method are (i) the difficulties with a reflection location on complex images due to overlapping problems and (ii) the curvature of the Ewald... 

The centre was calculated using the 4-click method. The minor axis was defined by picking the reflection 300 lying on the minor axis. The reflection was chosen for two reasons (i) it has high intensity and (ii) the distance from the centre is quite large. This allows defining the minor axis direction with high precision. 

---